Conventionally, there is a known air-conditioning unit for a vehicle equipped with a humidifier that humidifies the vehicle interior (see, for example, Patent Document 1). Patent Document 1 discloses an air-conditioning unit that includes permeable tubes designed to vaporize water and disposed in a duct to guide temperature-adjusted air into the vehicle interior, so that water stored in a tank is supplied to the permeable tubes, thereby humidifying the air before it is blown into the vehicle interior.